JP3243439B2 - Mold clamping mechanism for tire vulcanizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping mechanism for a tire vulcanizer, and more particularly to using a general-purpose pressure medium other than hydraulic pressure and utilizing the pressure to simplify a mold clamping structure. The present invention relates to a mold clamping mechanism for a tire vulcanizer capable of producing a high-quality vulcanized tire product with good yield and contributing to realization of a less expensive tire vulcanizer.

[0002]

2. Description of the Related Art In general, vulcanization in a tire vulcanizer is first performed.
The green tire is loaded into a pair of molds that can be opened and closed in the vertical direction, and at the same time, the bladder is placed inside the green tire and brought into close contact with the green tire, and then a bladder is blown into the bladder by blowing a pressurized heating medium. Indirectly through the method, a mold is pressed against the surface of the green tire to give a required external shape, and at the same time, the green tire is heated to be transformed into rubber. Then, when structurally looking at the tire vulcanizer, generally, the lower die of the pair of dies is fixed on a lower platen placed on the base of the vulcanizer, and the upper die is The upper and lower platen support members and the upper platen are fixed to an elevating member at a lower end of a mold opening / closing cylinder provided on a frame of the vulcanizer. A heat medium is inserted into the upper platen and the lower platen to heat the upper mold and the lower mold, respectively. Further, at the time of vulcanization, a mold clamping cylinder for holding a pair of molds for a certain period so as not to separate is generally provided on the frame of the vulcanizer similarly to the mold opening / closing cylinder, or Is provided directly on the mold, and is provided independently of the vulcanizer. In this case, a hydraulic cylinder is generally used as a mold clamping cylinder.

[0003] Further, most of the cycle time (about 10 minutes to 1 hour) in the tire vulcanization step is occupied by the vulcanization time in which the upper and lower molds are heated while being tightened. Operating time of auxiliary equipment is 1 to
Paying attention to the fact that the time is 2 minutes or less, a so-called multi-type tire vulcanizing system has been proposed in order to improve the operation efficiency of such ancillary equipment and improve the productivity of the tire. Further, in order to promote the realization of the multi-type tire vulcanizing system, there has been proposed a so-called self-locking mechanism capable of performing only a mold clamping operation independently of a vulcanizer body. For example, a self-locking mechanism (see FIG. 3) described in Japanese Patent Application Laid-Open No. 5-200754 is known.

[0004] That is, in FIG.
The upper disk 43 on which the molding die 42 on the side of the tire 40 is mounted, the lower disk 43 on which the molding die 44 on the other side of the tire 40 is mounted, and the numeral 45 is for molding the tread portion of the tire 40. This is a divided segment to which a divided mold 46 is attached. The divided segment 45 and the outer ring 47 provided further outside thereof are mounted so as to be slidably fitted to each other on their respective inclined surfaces. Further, at the upper and lower portions of each divided segment 45, there are provided projections 45a and 45b which engage with the upper disk 41 and the lower disk 43, respectively. The direction force is received by the projections 45a and 45b of the divided segment 45. That is, when high pressure acts on the bladder 48 during vulcanization, the outer ring 47 is lowered via the center mechanism 49. At this time, the so-called wedge action tightens the divided segments 45 in a radially inward direction, so to speak. Divided segment 45 and its projections 45a, 45b
And the molds 46, 42, and 44 are preloaded.

[0005]

However, as described above, there is a problem in the system using the hydraulic cylinder as the mold clamping cylinder. In other words, since oil leakage is inevitable in mold clamping with a hydraulic cylinder, oil easily adheres to the green tire, and once adhered, the appearance of the vulcanized tire deteriorates and the product value is lost. There are drawbacks. Needless to say, a separate device for securing a hydraulic pressure source as a pressure medium is required.

[0006] On the other hand, there is also a problem in the self-locking method using divided segments. That is, even if the effect of tightening the split mold from the circumferential direction outside by a wedge action using an inclined surface can be applied as a general self-locking mechanism, the self-locking at the time of vulcanization of the tire vulcanizing mold is possible. A sufficient effect cannot be obtained as a lock mechanism. This is because, after vulcanization, the mold must be opened smoothly. However, if the wedge action is strengthened too much in order to re-tighten too strongly, the outer ring 47 will separate the segment 45 when the mold is opened. This is because the wedge action can only be strengthened to a certain extent. Therefore, a gap is formed in the molds 46, 42, and 44 in the radial direction and the circumferential direction, and the tire during vulcanization may protrude from the gap, and a defective tire is easily generated. Further, since the inclined surfaces of the outer ring 47 and the divided segments 45 slide under a high pressure load, the sliding surfaces are very easily worn, and it is difficult to maintain the arrangement accuracy of the divided segments 45. Since the worn portion is not always uniform, the maintenance is complicated and the cost is considerable, for example, it is necessary to periodically inspect the worn portion and replace the corresponding segment 45.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. Among the present invention, the invention according to claim 1 uses a pressure medium as a mold clamping cylinder other than hydraulic pressure. By using a general-purpose and economical one and simplifying the mold clamping structure using the pressure, a high quality vulcanized product can be manufactured with good yield and a less expensive tire vulcanizer. It is an object of the present invention to provide a mold clamping mechanism for a tire vulcanizer that contributes to the realization of the above. Further, the invention of claim 2 provides, in addition to the object of the invention of claim 1, a mold clamping mechanism for a tire vulcanizer that can contribute to promoting the practical use of a multi-type vulcanization system. The purpose is to do.

[0008]

In order to achieve the above object, an invention according to claim 1 is provided with a pair of molds that can be opened and closed in a vertical direction and that has a green tire loaded therein, A bladder that is inserted inside and into which a pressurized heating medium is blown, formed of a disk-shaped cylinder case and a piston having a space larger than the diameter of the bladder, and a tightening unit that tightens the pair of dies. Wherein the pressure medium press-fitted into the cylinder case is the same as the pressurized heating medium blown into the bladder. This is a mold clamping mechanism for a tire vulcanizer.

Since a pressurized medium supplied into the bladder is used as the pressure source, it is possible to omit equipment and piping for securing a hydraulic pressure source which has been conventionally required. Further, since a heating medium such as steam is used as the pressurizing medium, a synergistic effect that the platen can be effectively heated can be obtained. In addition, since the cylinder case and the piston of the tightening means are formed in a disk shape having a space portion larger than the diameter of the bladder, a mold tightening cylinder can be easily configured. No need to equip. According to this mold clamping mechanism, as in the prior art,
There is no danger of defective tire products occurring due to oil adhesion, and the yield can be improved. Further, the manufacturing cost of the tire vulcanizer can be reduced in combination with the simple structure of the mold clamping cylinder as described above.

According to a second aspect of the present invention, a plurality of tie rods are provided around the mold to receive a reaction force of the fastening means in the mold clamping mechanism of the first aspect. This is a mold clamping mechanism for a tire vulcanizer that is compatible with a multi-type tire vulcanizing system.

[0011] This promotes the realization of a multi-type tire vulcanizing system that increases the operation efficiency of the auxiliary equipment of the tire vulcanizer and improves the productivity of the tire.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view schematically showing a tire vulcanizer having a mold clamping mechanism, and FIG. 2 is an enlarged sectional view of a main part showing the mold clamping mechanism. That is, as shown in FIG. 1, the tire vulcanizer has a base frame 1 fixed to a floor surface. A cylindrical tie rod 3 is provided upright at the center of the base frame 1, and the tie rod 3 is movably inserted into the center of the top slide 5 located above the base frame 1. I have.

The above-mentioned tie rod 3 is connected to the base frame 1
Has a base portion 3a fixed through the base portion, an intermediate portion 3b raised from the base frame 1, and a head portion 3c located at the uppermost portion, and between the head portion 3c and the intermediate portion 3b. Is formed with a circumferential groove 3d having a diameter smaller than the diameter of the head 3c and the intermediate portion 3b. And the circumferential groove 3
d, a pair of half blocks 4.4 are attached, and the half blocks 4.4 contact the lower surface of the head 3c of the tie rod 3 and the upper surface of the top slide 5 when the mold is tightened. Thereby, the top slide 5 and the base frame 1 are fixed via the tie rods 3.

The top slide 5 is provided with a pair of vulcanization molding portions 39 symmetrically arranged so that the tie rod 3 is located at the center. The mold clamping mechanism 8 is attached to these vulcanization molding sections 39. 8A
Is mold clamping means, 8B is mold height adjusting means, and the lower end of the clamping means 8A is in contact with the upper surface of the upper mold 16.

The above-mentioned tightening means 8A is a cap-shaped upper platen support member (cylinder case) 2 for further supporting a disk-shaped upper platen (piston) 15 from above.
2 are arranged while securing a predetermined space 23. The inner peripheral surface 22 b of the flange portion 22 a formed downward on the outer peripheral edge of the upper platen 15 is connected to the outer peripheral surface 1 of the lower platen 15.
5b is slidably fitted through a seal packing 26. The working fluid is press-fitted into the space 23 from the passage 31 by a fluid supply unit (not shown), and the configuration serves as a mold clamping unit. That is, the fastening means 8A
When the working fluid is press-fitted into the space 23, the upper platen 15, which is a piston, is urged toward the base frame 1 to generate a predetermined tightening force between the upper mold 16 and the lower mold 17. The reaction force at the time of tightening (the force that tries to open the top slide 5 and the base frame 1 by tightening) is received by the tie rod 3. On the other hand, when the working fluid is discharged, the upper platen 15 serving as a piston is drawn into the space 23 in the cylinder case. The working fluid press-fitted into the space 23,
That is, as the pressure medium, the same steam or the same inert gas as that supplied into the bladder 21 is used. However, since the diameter of the space 23 is larger than the diameter of the bladder 21 during tire vulcanization, vulcanization molding is performed. Sometimes the molds 16 and 17 do not open.

The tightening means 8A is supported by the top slide 5 via mold height adjusting means 8B. The mold height adjusting means has an adjusting screw 9 having an external thread portion 9 a formed on the outer peripheral surface of a rod member, and a nut member 13 rotatably fitted to the top slide 5. On the inner peripheral surface of the nut member 13, a female screw portion 13a screwed to the male screw portion 9a is formed. On the other hand, a protruding gear portion 13b is fixedly mounted on the outer peripheral surface of the nut member 13, so that the nut member 13 is vertically fixed. The protruding gear portion 13b is meshed with a pinion 14 rotatably supported by the top slide 5.

As described above, the nut member 13 is adapted to fix the tightening mechanism 8 having the adjusting screw 9 to the top slide 5 in the vertical direction by screwing with the adjusting screw 9, The rod member 9 is moved up and down by an amount corresponding to the amount of rotation when the member 14 is rotated by rotation driving means (not shown). An upper mold 16 is provided on the lower surface of the upper platen 15 provided in the tightening mechanism 8.
Numeral 6 is heated by a heating source of the upper platen 15 during vulcanization molding. Below the upper mold 16, a lower mold 17 is arranged, and the lower mold 17 and the upper mold 1 are arranged.
The green tire 7 is loaded into a cavity formed when the mold 6 is closed. Also, the lower mold 17
Is fixed to the base frame 1 via a lower platen 18 having a built-in heating source like the upper platen 15, and a central mechanism 19 is provided through the center of the lower mold 17. Support rings 19a and 19b, which constitute an intermediate portion of the center mechanism 19, support the bladder 21, and the bladder 21 urges the inner surface of the green tire 7 loaded in the cavity outward. ing.

The above-mentioned dies 16 and 15 and the tightening mechanism 8
The top slide 5 is supported by a frame elevating cylinder (not shown) and is movably engaged with a frame guide rail 30 erected in parallel with the axis of the tie rod 3. The top slide 5 is moved up along the frame guide rail 30 by the frame elevating cylinder, is pulled out from the tie rod 3, and can reach the highest position shown by the two-dot chain line in the drawing, while the frame is moved by the frame elevating cylinder. It descends along the guide rail 30, and can reach the lowest position shown by the solid line in the figure by inserting the tie rod 3.

The operation of the tightening mechanism 8 in the above configuration will be described. When the green tire 7 before vulcanization molding is conveyed between the upper mold 16 and the lower mold 17 of the vulcanization molding section 39 and placed on the lower mold 17, the top slide 5 is lowered to the lower limit position. Will be done. Then, the half blocks 4.4 are moved so as to be in contact with each other, so that the half blocks 4.4 are formed in the circumferential groove 3 d of the tie rod 3.
Will be fitted. As a result, the top slide 5 includes the half blocks 4.4, the circumferential groove 3d and the head 3c.
The tie rod 3 is fixed to the tie rod 3 by a lock mechanism comprising
Will be fixed.

Thereafter, as shown in FIG.
When the fluid such as steam is press-fitted into the space 23, and the upper platen 15, which is a piston, is pushed out, the upper mold 16 is pushed down in the direction of the lower mold 17, as shown in FIG. When the upper mold 16 and the lower mold 17 are clamped with a predetermined clamping force by pressing down the upper mold 16,
The upper mold 16 and the lower mold 17 are heated, and the inner surface of the green tire 7 loaded in the cavity is pressed by the bladder 21, whereby the green tire 7 is vulcanized.

Next, when vulcanizing green tires 7 having different specifications, the upper die 16 and the lower die 17 corresponding to the specifications of the green tire 7 are replaced. When the mold height changes due to the exchange of the molds 16 and 17, the pinion 14 is rotated so that the vertical position of the tightening mechanism 8 is adjusted according to the change in the mold height. become.

That is, the nut member 13 is screwed into the male screw portion 9a of the adjusting screw 9, and the adjusting screw 9
Is fixed so as not to rotate. Accordingly, when the nut member 13 rotates, the adjusting screw 9 moves in the vertical direction with the rotation of the nut member 13, so that the tightening mechanism 8 can be adjusted to correspond to the change in the mold height.

Thereafter, the green tire 7 before vulcanization molding is conveyed to the vulcanization molding section, and the green tire 7 is vulcanized in the vulcanization molding section 39 which has been clamped with a predetermined clamping force by the same operation as described above. It is to be sulfur molded.

Next, another embodiment of the present invention will be described with reference to FIG. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The characteristic feature lies in the configuration of the central part of the fastening means 8A and the mold height adjusting means 8B. That is, a cylindrical cylindrical guide portion 32 is provided at the center of the upper
2, and spaces 33, 34 which can move up and down along the outer peripheral surface 32a of the guide portion 32 are formed through the upper platen support member 22 and the adjusting screw 9, respectively. 38 is a seal packing. A disk-shaped upper platen 15 and a disk-shaped upper platen support member 22 that supports the disk-shaped upper platen 15 from above the predetermined space 23
Is secured and arranged. Each of the upper platen 15 and the upper platen support member 22 has a flange 1 around its periphery.
5a, 22a are formed, and each rising surface at the peripheral edge of the formation of the flange portion, that is, the flange portions 15a, 2a are formed.
Each of the peripheral side surfaces 15b and 22b of the short cylinder 2a
4 is slidably fitted to the inner peripheral surface 24b of the base member 4 via seal packings 26 and 27. Also, the flange portions 15a,
Reference numeral 22a denotes a bolt 28 holding the coil spring 30.
Therefore, when the upper platen 15 moves away from the upper platen support member 22, a force to pull them back acts on the upper platen 15.

As in the first embodiment, when a pressure medium such as steam or an inert gas is supplied to the space 23, the upper platen 15 as a piston is smoothly moved along the upper platen support member 22. To urge in the direction of the base frame 1 to reliably generate a predetermined tightening force between the upper mold 16 and the lower mold 17. The reaction force at the time of tightening (the force for opening the top slide 5 and the base frame 1 by tightening) is received by the plurality of tie rods 3 arranged around the die. On the other hand, when the pressure medium is discharged from the passage 31, the upper platen 15 serving as a piston is returned by the coil spring 30. Also in this case, the upper platen 15 smoothly returns by the guide action of the guide portion 32. With such a configuration, even if the upper platen, which is a piston, has a relatively thin thickness and a special cylinder structure having a small L / D as in the present embodiment, the upper platen 15 and the upper platen support member 22 are provided. As a structure that can maintain the parallelism of the piston, the smooth operation of the piston can be guaranteed, and the predetermined mold clamping can be more reliably performed.

In both the first embodiment and the second embodiment, the mold clamping mechanism 8 has a structure in which a conventional separately provided hydraulic cylinder is not required. That is, a general-purpose medium other than the hydraulic pressure, that is, the same as the supply medium to the bladder 21 is used as the pressure medium, and the upper platen 15 is a piston and the upper platen support member 22 is a cylinder. A simple case. That is, first of all, in terms of structure, the platen and the platen support member originally have a disk shape of substantially the same size, so for example, while reducing the diameter of the platen and performing groove processing for seal packing on the outer peripheral surface, By attaching a short tube to the outer peripheral edge of the platen support member to form a flange portion, by mounting such that the inner peripheral surface of the flange portion forms a sliding surface via the outer peripheral surface of the platen and a seal packing, Further, by forming the guide portion 23 at the center of the platen or the like, the mold clamping cylinder can be easily formed, and it is not necessary to separately provide a new clamping cylinder. Further, according to this mold clamping mechanism, unlike the related art, there is no possibility that defective tire products are generated due to oil adhesion, and the yield can be improved. Furthermore, since a pressurized medium supplied into the bladder is used as the pressure source, equipment and piping for securing a hydraulic source, which were conventionally required, can be omitted, and maintenance is facilitated. . Since a heating medium such as steam is used as the pressurizing medium, a synergistic effect that the platen can be effectively heated can be obtained. Therefore, the manufacturing cost of the tire vulcanizer can be reduced, in combination with the simple structure of the mold clamping cylinder as described above.

Further, the mold height adjusting means 8B is formed integrally with the mold clamping means 8A, and the adjusting means 8B has a simple structure by a screw feed system.
Even if the mold height changes depending on the type of tire, the mold clamping function by the clamping cylinder constituted by the upper platen 15 and the upper platen support member 22 can be reliably maintained. Tire vulcanizers that can exhibit excellent performance are also economical.

Also, in any of the embodiments, it is not necessary to consider the limitation on the clamping force to the mold, which has been a problem in the conventional self-locking mold clamping mechanism using the divided segments to which the wedge action is applied. Therefore, the dies 16 and 17 can be firmly tightened, and there is no possibility that the tire will protrude from the gap between the dies 16 and 17 during vulcanization, and the occurrence of defective tires can be avoided and the yield can be improved. Further, complicated maintenance such as inspection of the degree of wear of the split segments and replacement of worn split segments is not required. Therefore, it is possible to save costs and contribute to the reduction of the production cost of tire vulcanizers, and also to the tightening of tire vulcanizer molds that can contribute to the practical use of multi-vulcanization systems. A mechanism can be provided.

Although the mold clamping mechanism in the above embodiment is suitable for a tire vulcanizer having the structure shown in the drawings, various types of tires such as a frame-type frame type, a column lock type, a dome lock type, etc. It can be applied to a vulcanizer. Further, in the embodiment, the cylinder structure in which the upper platen is a piston and the upper platen support member is a cylinder case has been described. However, a cylinder structure in which the lower platen is a piston can of course be employed.

[0030]

As described above, the first aspect of the present invention uses a general-purpose and economical pressurized heating medium for bladders other than hydraulic pressure as a pressure medium as a mold clamping cylinder. In addition, the pressure is used to simplify the mold clamping structure by means of a disc-shaped piston having a space larger than the diameter of the bladder and a cylinder case, so that high quality vulcanized products can be produced. In addition to being able to produce with good yield, it has become possible to contribute to the realization of a less expensive tire vulcanizer.

According to the second aspect of the present invention, it is possible to provide a mold clamping mechanism for a tire vulcanizer that can contribute to promoting the practical use of a multi-curing system.

[Brief description of the drawings]

FIG. 1 is an explanatory front view schematically showing a tire vulcanizer having a mold clamping mechanism according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part showing a mold clamping mechanism according to another embodiment of the present invention.

FIG. 3 is an explanatory sectional view showing a main part of a conventional self-locking mold clamping mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base frame 3 Tie rod 4 Half block 5 Top slide 8 Die fastening mechanism 8A Die fastening means 8B Die height adjustment means 9 Adjusting screw 13 Nut member 15 Upper platen (piston) 16 Upper die 17 Lower die Reference Signs List 18 lower platen 21 bladder 22 upper platen support member (cylinder case) 23 space portion 24 cylinder 28 bolt 29 nut 30 coil spring 31 passage 32 guide portion 39 vulcanization molding portion

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-117940 (JP, A) JP-A-62-193809 (JP, A) Patent 2951576 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 33/02 B29C 33/24 B29C 35/02

Claims (2)

(57) [Claims] 1. A pair of molds which can be opened and closed in a vertical direction and has a green tire loaded therein, a bladder which is loaded inside the green tire and into which a pressure heating medium is blown, and a diameter of the bladder. A mold clamping mechanism for a tire vulcanizer, comprising: a disk-shaped cylinder case having a large space portion; and a piston, comprising: a clamping unit configured to clamp the pair of dies. A mold clamping mechanism for a tire vulcanizer, wherein a pressurized pressure medium is the same as a pressurized heating medium blown into the bladder. 2. The mold according to claim 1, wherein a plurality of tie rods are provided around the mold to receive a reaction force from the fastening means, so that the mold can be adapted to a multi-type tire vulcanizing system. Tightening mechanism.